1. Field of the Invention
The present invention relates to a connection system for connecting for example a marine vessel to a personnel ramp, thus allowing the transfer of personnel and/or material between the two. The present invention has been proven in the offshore marine industry in the transfer of personnel and/or material between a stationary object such as a platform and attached ramp and a moving object such as a boat, wherein the ramp-boat connection allows the boat to rotate, pivot and list in response to wave action.
2. Prior Art
One major problem facing the offshore industry today is the safe and efficient transfer of personnel and equipment between boats and fixed platforms. As industry goes farther offshore, wave heights in the neighborhood of 6 to 8 feet are relatively commonplace and can get to be much higher. The higher waves encountered frequently lead to delays, lost equipment dropped over the side and, in many instances, personal injury or loss of life. Additionally, high winds can become a negative factor. For example, out in the North Sea one can expect to be confronted with a wind blowing at 20 knots with 15 foot waves.
Several types of structures to permit transfers of personnel or cargo from two relatively moving objects, such as for example ships to other ships, or to stable objects such as for example platforms, have been known and used before in the prior art. Typical examples thereof in the moving boat to stable platform transfer art, which are actually and presently being used in the offshore marine industry, are a "monkey rope" system which is a rope hung from the stable platform wherein a man grabs the rope from the moving boat deck and swings to the platform; and a personnel basket system which is a rope-tied basket suspended from a cable and lowered by a service derrick located on the stable platform to transfer men and equipment from the platform to the deck of a moving boat or from the deck of a moving boat to the platform wherein the personnel hold on to the basket and are lifted to the structure by the crane; and finally a helicopter which permits the transfer through the airborne means between usually a land base to the stable platform. However, these actually used methods of the prior art either require considerable timing and dexterity on the part of the human operator to grasp for example the "monkey rope" when the boat deck is at the highest point of the swell and to be able to support his own weight and swing himself to the receiving deck and drop to safety there; or on the part of the crane operator in maneuvering the basket by his dexterity and ability, as well as an expensive crane structure and training that the crane operator must go through in order to safely transport people as well as the additional risk with human intervention of accidents occurring; or expensive equipment such as a helicopter which cannot operate during heavy weather; respectively.
Several types of direct attachment or ramp-type devices have also been known and used in the prior art to transfer cargo and personnel between ships or from ships to fixed platforms, and typical examples thereof in the marine transfer art are U.S. Pat. No. 3,064,829 issued Nov. 20, 1962 to Winfrey et al; U.S. Pat. No. 3,245,101 issued Apr. 12, 1966 to R. E. Wilson; U.S. Pat. No. 3,426,719 issued Feb. 11, 1969 to L. Mizell; U.S. Pat. No. 2,617,131 issued Nov. 11, 1952 to F. R. Harris; U.S. Pat. No. 3,228,051 issued Jan. 11, 1966 to Voase; U.S. Pat. No. 3,008,158 issued Nov. 14, 1961 to P. L. Stinson; U.S. Pat. No. 2,372,574 issued Mar. 27, 1945 to Haynes; U.S. Pat. No. 2,876,919 issued Mar. 10, 1959 to True, et al; U.S. Pat. No. 2,886,228 issued May 12, 1959 to Susikari; U.S. Pat. No. 3,095,848 issued July 2, 1963 to Dick; and U.S. Pat. No. 2,641,785 issued June 16, 1953 to Pitts, et al. Other patents of some interest to the general subjects of the present invention are the U.S. Pat. No. 3,067,716 issued Dec. 11, 1962 to Norlin, and U.S. Pat. No. 3,047,891 issued Aug. 7, 1962 to Golde, et al. However, none of these patents disclose a pivotal, rotational, yet solid connection between a ramp and a vessel.
It should be appreciated at the out-set that the present invention has solved a long standing problem and is satisfying a long felt need, whose solution and satisfaction has eluded the prior art workers lo these many years. Moreover, it should be further appreciated that the present invention is not based on a mere paper disclosure but rather is based on actual and successful use in the field.
3. Present Invention
In contrast to the prior art actually used in the offshore industry, which is incapable of safe, efficient, reliable, and inexpensive transfer of personnel and equipment from boats and platforms, the present invention in its most preferred embodiment utilizes a unique connection design which by means of its structure and attachment between the boat and the ramp or platform offers a more stable structural connection.
The invention provides a structural docking pedestal rigidly attached to a boat deck at preferably the centerline of the boat. An attachment assembly rotatably engages and latches to the docking pedestal. The attachment assembly is provided with a swivel connection on its upper surface for engaging the end portion of for example a boarding personnel ramp. The swivel connection allows both pivotal and rotational cooperation between the boat and the ramp.
Since the ramp attaching pedestal on the boat is preferably located on the center line of the boat, transverse activity is minimal at this point as compared to a point near the outboard side of the boat.
The activity of the ramp will never exceed the moving activity of the boat. Actually, when one steps on the ramp from the boat deck, the moving activity is identical, and will decrease proportionally as he walks toward the pivot deck. Attachment of the boat to the structure in the present invention is accomplished without outside assistance from anyone that is not on the boat. Because no one need be on the platform to assist with docking, this is especially important for unmanned or abandoned platforms.
Once moored to the platform by the unique attachment means of the present invention, the boat is significantly stabilized, thereby increasing the safety factor during the time it is necessary for men to walk on the boat's deck. It is noted that the most aggressive movements of a boat involves its transverse or rolling activity. The flexible ramp of the present invention is designed to conform to these transverse movements over its length in a directly proportional manner. No torsion exists in any of its members during the operation. The force necessary to reorient the ramp structure times the vertical distance from the metacenter of the boat offers a significant resistance moment.
Another method of additionally reducing the rolling activity of the boat allowed by the present invention is by engaging the boat engines and pulling against the ramp.
It is the combination of these resistances which are created or allowed by the present invention that renders significant stability to the rolling activity of the boat and an enhanced mooring capability. Although the most preferred embodiment of the present invention has a total mooring and stabilizing capability, additional mooring or stabilizing means or lines of course can be used as desired.
A quick release means is also provided in the present invention to permit the boat to immediately and completely disengage from the platform.
Docking is accomplished at considerable distance from the fixed structure due to the length of the ramp, thereby decreasing the damage potential to the boat or structure from collision of the two. Additionally, because the docking means is uniquely designed for ease of operation, the system is useful even in smooth waters. Reaction of the structure due to wave movements is less than if the boat were tied to the structure by a mooring line.
The present invention also allows considerable time saving because of its unique and easy means of attachment between the moving ship and the stationary platform in even very rough seas. Therefore, shut in wells can be reactivated as soon as the boat can get to the location; whereas, presently, boats frequently get out to the platform and then have to wait several hours before they can transfer crew and cargo because of wave heights. Under the present invention, as long as the boat can make the trip to the platform, the crew will be able to disembark.
Furthermore, the attachment means on the boat that engages the platform uses a very small deck area, thereby permitting better utilization of the boat deck area.
Moreover, a standard deck winch is used to pull the boat and the ramp together for attachment. This winch is equipped so that it will pay out under excessive loads and continue to pull in after the excessive load has passed. This will prevent undue shock to the entire system.
Also, this winch system allows the boat operator to continue applying the winch, even after the attachment is complete, without fear of breaking anything. It is this freedom from precise decision on the part of the boat operator that makes this system safe and usable for all boat "skippers".
Moreover, the boat activity is that of constantly pulling without slacking off, further simplifying the judgements needed by the boat operator.
It is noted that the ramp of the present invention can be used in all weather conditions and is only limited by the ability of the boat, to which the ramp is being connected, to operate. In order to not unnecessarily increase the costs of a particular installation, however, a ramp will usually be designed to handle a given size boat in conditions under which that boat can operate safely. However, a ramp and connection could be designed in accordance with the principles of the present invention to handle a battleship in a hurricane if cost factors were not a concern.
Thus, in summary, a basic, over-all object of the present invention is to provide a flexible yet structurally adequate connection system for connecting a boat to a ramp or platform.
Another object of the present invention is to provide a boat connection system which is safe, requiring a minimum of human involvement with the actual connection apparatus during the critical connection when high stresses cause injury.
A further object of the present invention is to provide a simple connection system between a vessel and for example a ramp which requires little operator skill to guide the connection parts together.
A final object of the present invention is to provide a boat/ramp connection system which is a paragon of simplicity, requiring only basic staple commodities for construction, thus providing an economical system.